Quantitative mapping of high modulus materials at the nanoscale: comparative study between atomic force microscopy and nanoindentation.

Local mechanical properties of submicron features are of particular interest due to their influence on macroscopic material performance and behaviour. This study is focused on local nanomechanical measurements, based on the latest Atomic Force Microscopy (AFM) mode, where the peak force set point is finely controlled at each pixel. After probe calibration, we evaluate the impact of spring constant of two AFM hand-crafted natural full diamond tips with steel cantilevers, used for mapping. Based on the fast capture of the cantilever deflection at each pixel and real time force curve analysis in the elastic region, AFM local measured contact moduli mappings of the silica beads (>50 GPa) incorporated in an epoxy resin matrix, are compared with those determined using classical instrumented nanoindentation tests. Our analyses show that with the two AFM probes, without local residual deformation, the high moduli of the silica beads measured with this advanced AFM mode are within the standard deviation of the values determined by classical nanoindentation. LAY DESCRIPTION: The knowledge of material properties at the nanometer scale is a key parameter for well understanding and determining the behavior of material at macroscopic scale. In this paper, we compare two methods (an advanced mode and a classical one) based on the analysis of probes in interaction with the surface of studied material. We focus on a latest developed mode for determining local mechanical properties with a very high spatial resolution. For the advanced mode, we also consider two different hand-crafted probes. Our analyses show that with the high spatial resolution advanced mode, local mechanical properties are well determined. We also highlight the impact of the properties of the used probes for this advanced mode. In a final step, the power of the presented investigation lies in the fact that it does not modify the topography of the surface.

First case of spontaneous rupture of the left ureter in immediate post-partum.

The rupture of the ureter during pregnancy is a rare complication and is most frequently observed in the right ureter. We report below the case of a rupture in the left ureter. A 36-year old woman gave birth vaginally to a 3010-g girl without operative vaginal delivery or episiotomy. The following day, the patient exhibited a sudden pain in the left side spreading to the left iliac fossa. An abdominopelvic CT scan was carried out and revealed a flow of contrast agent at the left ureteral lumbar level and a left urinoma. A ureteral stent was inserted on the left side under X-ray control. Six weeks after delivery the ureteral stent was removed. The Uro CT scan allowed us to confirm the total recovery of the left ureter. We have reported below the first case of left rupture treated in a conservative manner with positive and functional clinical progress.

Can the risks associated with uterine sarcoma morcellation really be prevented? Overview of the role of uterine morcellation in 2018.

OBJECTIVES: The objective of this literature review is to reiterate the epidemiology, clinical signs, and radiological signs that should be consistent with a uterine sarcoma as well as the precautionary pre- and postoperative principles that help prevent morcellation of uterine sarcomas when treating patients with uterine fibroids. METHOD: We conducted this literature review by consulting the Pubmed, Medline, and Cochrane Systematic Review databases up to 28/02/2017 using the following keywords: fibroid, myoma, leiomyoma, sarcoma, leiosarcoma, uterine cancer, myomectomy, hysterectomy, morcellation, and uterine morcellation. We also used the reference lists of the selected articles to find more data on the websites of North-American and European learned societies that specialise in obstetrics and gynaecology. RESULTS: In the case of morcellation of uterine fibroids, the risk of an undiagnosed uterine sarcoma is estimated to be between 1 in 278 to 1 in 1960 women. Preoperative examination, free informed consent following discussion about the risks and complications associated with morcellation, as well as research on the contraindications to the use of morcellation are the crucial points addressed by learned societies. The main solution recommended at present is morcellation confined to a laparoscopic bag. CONCLUSION: There is a risk of morcellating an occult sarcoma when performing a myomectomyor hysterectomy for fibroids. Implementing the use of morcellation containment bags should be the norm. The use of minimally invasive surgery (laparoscopic orvaginal) and the associated benefit-risk ratio compared to a laparotomy should also be discussed with the patient before the operation.

Influence of ultrasonographers training on prenatal diagnosis of congenital heart diseases: a 12-year population-based study.

OBJECTIVE: Since 1998, French multidisciplinary prenatal diagnosis centers (CPDPN) offer a training opportunity to first-level screening sonographers. This study measures the impact of this training on prenatal detection rates of congenital heart diseases (CHDs). METHODS: We analyzed the sensitivity of screening sonographers by comparing CHD prenatal diagnoses and CHDs observed after birth in the area of Angers from 1994 to 2006. Two groups of sonographers were compared, those who attended the training (n=19) and those who did not (control group. n=21). The evolution of CHD detection rate was compared between two successive periods of 6 years each. RESULTS: Of 947 CHDs, 438 (46%) were detected prenatally. The control group sensitivity was 16 versus 37% for the sonographers who had attended the training course (p<0.001).Between the two study periods, detection rates for all CHDs and significant CHDs remained unchanged in the control group, whereas they improved significantly in the other group (respectively 54% vs 33% and 75% vs 38%, p<0.05). CONCLUSION: This study supports the hypothesis of a beneficial effect of CPDPN on prenatal diagnosis of CHDs. These centers not only fulfill their primary purpose but also operate as learning centers in which screening sonographers may improve their practice.